Dirt Bike Engine
Dirt Bike Engine Parts at JJ Motorsports
Discover a full range of dirt bike engine components for rebuilding or upgrading your performance from JJ Motorsports. From crankshafts to cylinder heads and piston kits, these precision-engineered components ensure reliable performance. For additional upgrades, check out our full selection of off-road dirt bike parts to keep your engine running at peak efficiency on the track or trails.
Shop trusted brands like Wiseco for forged piston kits and K&N for high-flow oil filters. Explore related categories such as Dirt Bike Air and Fuel for intake upgrades or Dirt Bike Exhaust for complete systems.
Browse our in-stock inventory below with same-day shipping and expert support. Questions? Contact us for fitment advice!
- Product
- Qty in Cart
- Quantity
- Price
- Subtotal
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WSM Rotary Valve Gear 010-450
WSM
$45.26If your Sea-Doo's rotary valve isn't operating at peak efficiency, power delivery and throttle response suffer—and so does your watercraft's overall performance. The WSM Rotary Valve Gear 010-450 is a direct replacement engineered to restore precise...010450- SKU:
- 010450
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- UNITS:
- EACH
- PRODUCT NAME:
- GEAR
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- ROTARY VALVE
$45.26 -
WSM Rotary Valve Shaft 010-455
WSM
$86.94The WSM Rotary Valve Shaft 010-455 is essential for maintaining precise intake timing and fuel delivery in your Sea-Doo engine. A worn or damaged rotary valve shaft compromises performance and can lead to costly engine damage if left unaddressed. This...010455- SKU:
- 010455
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- MATERIAL:
- STEEL
- PRODUCT NAME:
- SHAFT
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- ROTARY VALVE
- UNITS:
- EACH
$86.94 -
WSM Top-End Rebuild Kit - Original Series - Standard 010-802-10
WSM
$247.87A top-end rebuild is essential maintenance for any high-performance engine, and the WSM Original Series kit delivers OEM-quality components at a fraction of full-engine rebuild costs. This comprehensive piston kit includes everything needed for a...01080210- SKU:
- 01080210
- Availability:
- Ships Same Business Day
- Weight:
- 2.60 LBS
- BORE - OVERSIZE METRIC:
- STANDARD
- PRODUCT NAME:
- REBUILD KIT
- UNITS:
- EACH
- BORE SIZE METRIC:
- 77.00 MM
- MODEL:
- ORIGINAL SERIES
- TYPE:
- TOP END
- BORE - OVERSIZE:
- STANDARD
- RIDING STYLE:
- WATERCRAFT
- PISTON MATERIAL:
- ALUMINUM
$247.87 -
WSM Piston Kit - Kawasaki - +.25 mm 010-810-04K
WSM
$86.28When you're pushing your Kawasaki to the limit, stock pistons become your performance ceiling. The WSM Piston Kit delivers OEM-matching quality with critical upgrades—MOS2-coated skirts that actively dissipate heat while reducing friction, and specially...01081004- SKU:
- 01081004
- Availability:
- Ships Same Business Day
- Weight:
- 0.81 LBS
- BORE - OVERSIZE:
- +0,25 MM
- BORE - OVERSIZE METRIC:
- +0.25 MM
- BORE SIZE METRIC:
- 76.00 MM
- MODEL:
- ORIGINAL
- PRODUCT NAME:
- PISTON KIT
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
$86.28 -
WSM Piston Kit - Kawasaki 650 - +.5 mm 010-810-05K
WSM
$86.28If you're rebuilding or upgrading your Kawasaki 650, piston quality directly impacts combustion efficiency, heat management, and engine longevity. The WSM Piston Kit delivers OEM-equivalent construction with purposeful upgrades—specifically the MOS2...01081005- SKU:
- 01081005
- Availability:
- Ships Same Business Day
- Weight:
- 0.81 LBS
- BORE - OVERSIZE METRIC:
- +0.50 MM
- RIDING STYLE:
- WATERCRAFT
- MODEL:
- ORIGINAL
- PISTON MATERIAL:
- ALUMINUM
- BORE SIZE METRIC:
- 76.00 MM
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE:
- +0,50 MM
- UNITS:
- KIT
$86.28 -
WSM Top-End Rebuild Kit - Original Series - Standard 010-810-10
WSM
$252.25A top-end rebuild demands precision components that restore your engine to factory specifications or better. The WSM Top-End Rebuild Kit eliminates the guesswork of sourcing individual gaskets, rings, and bearings by bundling everything you need in one...01081010- SKU:
- 01081010
- Availability:
- Ships Same Business Day
- Weight:
- 2.55 LBS
- MODEL:
- ORIGINAL SERIES
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 76.00 MM
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- TOP END
- UNITS:
- EACH
$252.25 -
WSM Piston Kit - Kawasaki 550 - +.5 mm 010-812-05K
WSM
$81.73If you're building or rebuilding a Kawasaki 550 engine, piston quality directly impacts reliability, power output, and engine longevity. WSM pistons are engineered to OEM or better standards with advanced coatings and hardened construction that reduce...01081205- SKU:
- 01081205
- Availability:
- Ships Same Business Day
- Weight:
- 0.70 LBS
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE:
- +0,50 MM
- BORE - OVERSIZE METRIC:
- +0.50 MM
- BORE SIZE METRIC:
- 75.00 MM
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
- MODEL:
- ORIGINAL
$81.73 -
WSM Top-End Rebuild Kit - Original Series - Standard 010-812-10
WSM
$205.60A top-end rebuild is essential when your engine shows signs of wear—loss of compression, increased blow-by, or declining power output. The WSM Top-End Rebuild Kit delivers OEM-quality components engineered to restore your engine to factory specifications...01081210- SKU:
- 01081210
- Availability:
- Ships Same Business Day
- Weight:
- 2.45 LBS
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE - OVERSIZE:
- STANDARD
- BORE SIZE METRIC:
- 75.00 MM
- UNITS:
- EACH
- MODEL:
- ORIGINAL SERIES
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- TOP END
$205.60 -
WSM Top-End Rebuild Kit - Original Series - Standard 010-816-10
WSM
$223.48A top-end rebuild is essential when your engine shows signs of wear—loss of compression, increased blow-by, or declining power output. The WSM Top-End Rebuild Kit delivers OEM-quality components engineered to restore your engine to factory specifications...01081610- SKU:
- 01081610
- Availability:
- Ships Same Business Day
- Weight:
- 2.88 LBS
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- PRODUCT NAME:
- REBUILD KIT
- MODEL:
- ORIGINAL SERIES
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- TOP END
- UNITS:
- EACH
- BORE SIZE METRIC:
- 78.00 MM
$223.48 -
WSM Top-End Rebuild Kit - Original Series - .50 mm 010-816-12
WSM
$223.48A top-end rebuild demands precision components that can withstand extreme combustion pressures and sustained high RPM operation. The WSM Original Series Kit delivers factory-quality pistons paired with complete gasket and bearing assemblies, eliminating...01081612- SKU:
- 01081612
- Availability:
- Ships Same Business Day
- Weight:
- 2.90 LBS
- PRODUCT NAME:
- REBUILD KIT
- UNITS:
- EACH
- MODEL:
- ORIGINAL SERIES
- BORE - OVERSIZE METRIC:
- +0.50 MM
- BORE SIZE METRIC:
- 78.50 MM
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- TOP END
- BORE - OVERSIZE:
- +0,50 MM
- PISTON MATERIAL:
- ALUMINUM
$223.48 -
WSM Piston Kit - Sea-Doo 720 - Standard 010-817K
WSM
$89.33A quality piston kit is the foundation of reliable engine performance, and the WSM 010-817K delivers OEM-equivalent construction with engineered improvements for reduced heat and friction. The MOS2 coating on the skirts actively draws heat away from the...010817- SKU:
- 010817
- Availability:
- Ships Same Business Day
- Weight:
- 1.13 LBS
- BORE SIZE METRIC:
- 82.00 MM
- PISTON MATERIAL:
- ALUMINUM
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- MODEL:
- ORIGINAL
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
$89.33 -
WSM Piston Kit - Sea-Doo 720 - +.25 mm 010-817-04K
WSM
$89.33A piston kit failure can sideline your Sea-Doo 720 when you need it most. WSM's +.25 mm oversize pistons deliver OEM-equivalent quality with engineering upgrades specifically designed to reduce friction, lower operating temperatures, and extend engine...01081704- SKU:
- 01081704
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- BORE - OVERSIZE:
- +0,25 MM
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE METRIC:
- +0.25 MM
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
- BORE SIZE METRIC:
- 82.00 MM
- MODEL:
- ORIGINAL
$89.33 -
WSM Piston Kit - Sea-Doo 720 - +.5 mm 010-817-05K
WSM
$89.33When you're running a Sea-Doo 720 at the limit, stock pistons become the weak link. The WSM Piston Kit delivers OEM-quality construction with measurable upgrades—specifically the MOS2 coating on the skirts that actively dissipates heat while reducing...01081705- SKU:
- 01081705
- Availability:
- Ships Same Business Day
- Weight:
- 1.13 LBS
- BORE - OVERSIZE:
- +0,50 MM
- MODEL:
- ORIGINAL
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE METRIC:
- +0.50 MM
- BORE SIZE METRIC:
- 82.00 MM
- PRODUCT NAME:
- PISTON KIT
$89.33 -
WSM Piston Kit - Sea-Doo 800 - Standard 010-818K
WSM
$89.33Sea-Doo 800 engines demand precision-engineered internals to handle sustained high-RPM performance, and OEM pistons often fall short in durability under aggressive use. The WSM Piston Kit delivers OEM-equivalent quality with meaningful...010818- SKU:
- 010818
- Availability:
- Ships Same Business Day
- Weight:
- 1.75 LBS
- BORE SIZE METRIC:
- 82.00 MM
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- MODEL:
- ORIGINAL
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- WATERCRAFT
$89.33 -
WSM Piston Kit - Sea-Doo 800 - +1 mm 010-818-07K
WSM
$89.33When you're pushing a Sea-Doo 800 to its limits, factory pistons become a liability. The WSM Piston Kit delivers OEM-quality construction with engineered improvements—notably the MOS2 coating that actively dissipates heat and reduces friction for...01081807- SKU:
- 01081807
- Availability:
- Ships Same Business Day
- Weight:
- 1.30 LBS
- BORE - OVERSIZE:
- +1,00 MM
- BORE SIZE METRIC:
- 82.00 MM
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE METRIC:
- +1.00 MM
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
- MODEL:
- ORIGINAL
$89.33 -
WSM Piston Kit - Sea-Doo 951 - +.25 mm 010-819-04K
WSM
$98.28If you're pushing your Sea-Doo 951 to the limit, factory pistons won't cut it—they'll give up first. This WSM Piston Kit delivers OEM-quality construction with engineering upgrades that reduce heat and friction, giving you more power, better reliability,...01081904- SKU:
- 01081904
- Availability:
- Ships Same Business Day
- Weight:
- 1.50 LBS
- MODEL:
- ORIGINAL
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
- BORE - OVERSIZE:
- +0,25 MM
- BORE SIZE METRIC:
- 87.91 MM
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE METRIC:
- +0.25 MM
- PRODUCT NAME:
- PISTON KIT
$98.28 -
WSM Piston Kit - Sea-Doo 951 - +.5 mm 010-819-05K
WSM
$98.28If you're rebuilding a Sea-Doo 951 engine or pushing past factory limits, piston quality directly determines whether your engine lives or fails under load. The WSM Piston Kit delivers OEM-equivalent construction with performance-oriented...01081905- SKU:
- 01081905
- Availability:
- Ships Same Business Day
- Weight:
- 0.78 LBS
- BORE - OVERSIZE METRIC:
- +0.50 MM
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE:
- +0,50 MM
- UNITS:
- KIT
- BORE SIZE METRIC:
- 87.91 MM
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- MODEL:
- ORIGINAL
$98.28 -
WSM Top-End Rebuild Kit - Original Series - Standard 010-819-10
WSM
$330.79A top-end rebuild is the most direct path to restoring lost compression, sealing blow-by, and recovering horsepower in a worn engine. The WSM Original Series kit eliminates the guesswork by bundling every critical component you need—pistons, rings, and...01081910- SKU:
- 01081910
- Availability:
- Ships Same Business Day
- Weight:
- 4.05 LBS
- BORE - OVERSIZE:
- STANDARD
- TYPE:
- TOP END
- UNITS:
- EACH
- BORE SIZE METRIC:
- 87.91 MM
- MODEL:
- ORIGINAL SERIES
- PRODUCT NAME:
- REBUILD KIT
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE METRIC:
- STANDARD
- PISTON MATERIAL:
- ALUMINUM
$330.79 -
WSM Piston Kit - Kawasaki - Standard 010-820K
WSM
$89.33If you're running a Kawasaki engine that demands reliability under sustained high RPM, a quality piston kit is non-negotiable—it's the foundation of durability when power levels climb. The WSM Piston Kit delivers OEM-matching construction with genuine...010820- SKU:
- 010820
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- MODEL:
- ORIGINAL
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- WATERCRAFT
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
- BORE SIZE METRIC:
- 80.00 MM
$89.33 -
WSM Piston Kit - Kawasaki 750 - +.5 mm 010-820-05K
WSM
$89.33Piston wear is one of the fastest paths to catastrophic engine failure, especially in high-performance Kawasaki 750 applications where heat and friction compound stress on critical components. The WSM Piston Kit delivers OEM-equivalent quality with...01082005- SKU:
- 01082005
- Availability:
- Ships Same Business Day
- Weight:
- 0.13 LBS
- BORE - OVERSIZE METRIC:
- +0.50 MM
- BORE SIZE METRIC:
- 80.00 MM
- BORE - OVERSIZE:
- +0,50 MM
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
- MODEL:
- ORIGINAL
- PRODUCT NAME:
- PISTON KIT
$89.33
